Depending on what exactly you've got in mind by 'mark the document' you can use the essay question type.
Put the text for the student in the 'Reponse template' and set the response options accordingly.
Now your students can discuss the text.
If you want to go a step further, you can make use of the essay autograde question (additional plugin) to mark students answers 'automatically'. Or at least help your teachers marking the answers.